Replace ecs::container::describe() with describe_short() and describe_detailed(), and introduce entity inspection API

libs/ecs/include/psemek/ecs/accessor.hpp

@@ -3,8 +3,6 @@
 #include <psemek/ecs/exceptions.hpp>
 #include <psemek/ecs/detail/table.hpp>
 
-#include <typeindex>
-
 namespace psemek::ecs
 {
 
@@ -55,6 +53,19 @@ namespace psemek::ecs
 		template <typename Component>
 		Component const & get() const;
 
+		/** Obtain the component by uuid of the accessed entity.
+		 *  As the runtime type of the component is unknown,
+		 *  the function returns pointer-to-void.
+		 *
+		 *  @param uuid The uuid of component to obtain
+		 *  @return A pointer to the component of the specified type, or a null
+		 *    pointer if the entity doesn't contain a component of this type
+		 *  @pre The accessor is valid
+		 */
+		void * get_if(util::uuid const & uuid);
+
+		void const * get_if(util::uuid const & uuid) const;
+
 		/** Check if the entity contains this component type.
 		 *
 		 *  @tparam Component The type of component to obtain
@@ -98,12 +109,7 @@ namespace psemek::ecs
 	Component const * accessor::get_if() const
 	{
 		util::uuid const uuid = std::remove_const_t<Component>::uuid();
-
+		return reinterpret_cast<Component const *>(get_if(uuid));
-		auto column = table_->column(uuid);
-		if (!column)
-			return nullptr;
-
-		return reinterpret_cast<Component *>(column->data() + detail::stride<std::remove_const_t<Component>>() * row_);
 	}
 
 	template <typename Component>
@@ -111,7 +117,7 @@ namespace psemek::ecs
 	{
 		if (auto ptr = get_if<Component>())
 			return *ptr;
-		throw component_not_found_exception(typeid(std::remove_const_t<Component>), table_->entity_handles()[row_], table_->describe(row_));
+		throw component_not_found_exception(typeid(std::remove_const_t<Component>), table_->entity_handles()[row_], table_->describe_short());
 	}
 
 	template <typename Component>
@@ -119,7 +125,21 @@ namespace psemek::ecs
 	{
 		if (auto ptr = get_if<Component const>())
 			return *ptr;
-		throw component_not_found_exception(typeid(std::remove_const_t<Component>), table_->entity_handles()[row_], table_->describe(row_));
+		throw component_not_found_exception(typeid(std::remove_const_t<Component>), table_->entity_handles()[row_], table_->describe_short());
+	}
+
+	inline void * accessor::get_if(util::uuid const & uuid)
+	{
+		return const_cast<void *>(static_cast<accessor const *>(this)->get_if(uuid));
+	}
+
+	inline void const * accessor::get_if(util::uuid const & uuid) const
+	{
+		auto column = table_->column(uuid);
+		if (!column)
+			return nullptr;
+
+		return column->data() + column->stride() * row_;
 	}
 
 	template <typename Component>

libs/ecs/include/psemek/ecs/container.hpp

@@ -11,6 +11,7 @@
 #include <psemek/ecs/detail/index_container.hpp>
 #include <psemek/ecs/detail/recursion_depth_guard.hpp>
 #include <psemek/ecs/accessor.hpp>
+#include <psemek/ecs/inspect.hpp>
 #include <psemek/ecs/exceptions.hpp>
 #include <psemek/ecs/statistics.hpp>
 #include <psemek/util/range.hpp>
@@ -95,14 +96,33 @@ namespace psemek::ecs
 		 */
 		accessor get(handle entity);
 
-		/** Compute a string representation of an entity, based on the contained components.
+		/** Inspect the entity, i.e. enumerate the entitie's components.
-		 *  A component has to implement a to_string() method in order to provide extra info.
 		 *
-		 *  @param entity A handle to the entity to describe
+		 *  @param entity A handle to the entity to inspect
-		 *  @return A string representation of an entity
+		 *  @return A list of component uuids & metadata
 		 *  @pre The entity was previously obtained by a `create()` call and is `alive()`
 		 */
-		std::string describe(handle entity) const;
+		entity_inspection_info inspect(handle entity) const;
+
+		/** Compute a short string representation of an entity, based on the contained components.
+		 * The short version just enumerates the component types, separated by ';'.
+		 *
+		 *  @param entity A handle to the entity to describe
+		 *  @return A short string representation of an entity
+		 *  @pre The entity was previously obtained by a `create()` call and is `alive()`
+		 */
+		std::string describe_short(handle entity) const;
+
+		/** Compute a detailed string representation of an entity, based on the contained components.
+		 * A component has to implement a to_string() method in order to provide extra info.
+		 * The detailed version lists all components together with their data (as provided by
+		 * component.to_string) in a large multi-line string.
+		 *
+		 *  @param entity A handle to the entity to describe
+		 *  @return A detailed string representation of an entity
+		 *  @pre The entity was previously obtained by a `create()` call and is `alive()`
+		 */
+		std::string describe_detailed(handle entity) const;
 
 		/** Check if the entity can be cloned.
 		 *

libs/ecs/include/psemek/ecs/detail/column.hpp

@@ -1,7 +1,7 @@
 #pragma once
 
 #include <psemek/ecs/detail/stride.hpp>
-#include <psemek/ecs/detail/describe.hpp>
+#include <psemek/ecs/detail/to_string.hpp>
 #include <psemek/util/uuid.hpp>
 #include <psemek/util/assert.hpp>
 
@@ -33,6 +33,11 @@ namespace psemek::ecs::detail
 			return uuid_;
 		}
 
+		std::string const & name() const
+		{
+			return name_;
+		}
+
 		std::type_index const & type() const
 		{
 			return type_;
@@ -54,21 +59,20 @@ namespace psemek::ecs::detail
 
 		virtual std::size_t memory_usage() const = 0;
 
-		virtual std::string describe() const = 0;
-		virtual std::string describe(std::uint32_t row) const = 0;
-
 		virtual ~column() = default;
 
 	protected:
 		std::uint8_t * data_ = nullptr;
 		std::size_t stride_;
 		util::uuid uuid_;
+		std::string name_;
 		std::type_index type_;
 		bool copy_constructible_;
 
-		column(std::size_t stride, util::uuid const & uuid, std::type_index const & type, bool copy_constructible)
+		column(std::size_t stride, util::uuid const & uuid, std::string name, std::type_index const & type, bool copy_constructible)
 			: stride_(stride)
 			, uuid_(uuid)
+			, name_(std::move(name))
 			, type_(type)
 			, copy_constructible_(copy_constructible)
 		{}
@@ -91,9 +95,6 @@ namespace psemek::ecs::detail
 
 		std::size_t memory_usage() const override;
 
-		std::string describe() const override;
-		std::string describe(std::uint32_t row) const override;
-
 		~column_impl() override;
 
 	private:
@@ -120,15 +121,12 @@ namespace psemek::ecs::detail
 
 		std::size_t memory_usage() const override;
 
-		std::string describe() const override;
-		std::string describe(std::uint32_t row) const override;
-
 		~column_impl() override;
 	};
 
 	template <typename Component, bool Empty>
 	column_impl<Component, Empty>::column_impl()
-		: column(detail::stride<Component>(), Component::uuid(), typeid(Component), std::is_copy_constructible_v<Component>)
+		: column(detail::stride<Component>(), Component::uuid(), component_name<Component>(), typeid(Component), std::is_copy_constructible_v<Component>)
 	{}
 
 	template <typename Component, bool Empty>
@@ -218,18 +216,6 @@ namespace psemek::ecs::detail
 		return sizeof(Component) * row_count_;
 	}
 
-	template <typename Component, bool Empty>
-	std::string column_impl<Component, Empty>::describe() const
-	{
-		return detail::describe<Component>();
-	}
-
-	template <typename Component, bool Empty>
-	std::string column_impl<Component, Empty>::describe(std::uint32_t row) const
-	{
-		return detail::describe(reinterpret_cast<Component const *>(data_)[row]);
-	}
-
 	template <typename Component, bool Empty>
 	column_impl<Component, Empty>::~column_impl()
 	{
@@ -267,7 +253,7 @@ namespace psemek::ecs::detail
 
 	template <typename Component>
 	column_impl<Component, true>::column_impl()
-		: column(detail::stride<Component>(), Component::uuid(), typeid(Component), std::is_copy_constructible_v<Component>)
+		: column(detail::stride<Component>(), Component::uuid(), component_name<Component>(), typeid(Component), std::is_copy_constructible_v<Component>)
 	{
 		data_ = reinterpret_cast<std::uint8_t *>(new Component[1]);
 	}
@@ -308,18 +294,6 @@ namespace psemek::ecs::detail
 		return sizeof(Component);
 	}
 
-	template <typename Component>
-	std::string column_impl<Component, true>::describe() const
-	{
-		return detail::describe<Component>();
-	}
-
-	template <typename Component>
-	std::string column_impl<Component, true>::describe(std::uint32_t) const
-	{
-		return detail::describe(*reinterpret_cast<Component const *>(data_));
-	}
-
 	template <typename Component>
 	column_impl<Component, true>::~column_impl()
 	{

libs/ecs/include/psemek/ecs/detail/component_registry.hpp

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <psemek/ecs/detail/column.hpp>
+#include <psemek/ecs/detail/to_string.hpp>
 #include <psemek/util/uuid.hpp>
 #include <psemek/util/hash_table.hpp>
 #include <psemek/util/function.hpp>
@@ -32,36 +33,54 @@ namespace psemek::ecs::detail
 
 	struct component_registry
 	{
+		struct component_info
+		{
+			std::string name;
+			std::type_info const * type_info;
+			util::function<std::unique_ptr<column>()> column_factory;
+			util::function<std::string(void const *)> to_string;
+		};
+
 		template <typename Component>
 		void register_component()
 		{
 			auto const & uuid = Component::uuid();
 
-			if (auto it = types_.find(uuid); it != types_.end())
+			if (auto it = components_.find(uuid); it != components_.end())
 			{
-				if (it->second != &typeid(Component))
+				if (it->second.type_info != &typeid(Component))
-					throw duplicate_uuid_exception(uuid, *(it->second), typeid(Component));
+					throw duplicate_uuid_exception(uuid, *(it->second.type_info), typeid(Component));
 				else
 					return;
 			}
 
-			types_.insert({uuid, &typeid(Component)});
+			component_info & info = components_[uuid];
-
+			info.name = component_name<Component>();
-			column_factories_.insert({uuid, []{
+			info.type_info = &typeid(Component);
+			info.column_factory = []{
 				return std::make_unique<column_impl<Component>>();
-			}});
+			};
+			info.to_string = [](void const * data){
+				return component_to_string(*static_cast<Component const *>(data));
+			};
 		}
 
 		std::unique_ptr<column> create_column(util::uuid const & uuid) const
 		{
-			if (auto it = column_factories_.find(uuid); it != column_factories_.end())
+			if (auto it = components_.find(uuid); it != components_.end())
-				return it->second();
+				return it->second.column_factory();
+			return nullptr;
+		}
+
+		component_info const * get_info(util::uuid const & uuid) const
+		{
+			if (auto it = components_.find(uuid); it != components_.end())
+				return &it->second;
 			return nullptr;
 		}
 
 	private:
-		util::hash_map<util::uuid, std::type_info const *> types_;
+		util::hash_map<util::uuid, component_info> components_;
-		util::hash_map<util::uuid, util::function<std::unique_ptr<column>()>> column_factories_;
 	};
 
 }

libs/ecs/include/psemek/ecs/detail/describe.hpp

@@ -1,39 +0,0 @@
-#pragma once
-
-#include <psemek/util/type_name.hpp>
-
-#include <string>
-
-namespace psemek::ecs::detail
-{
-
-	template <typename Component>
-	std::string describe()
-	{
-		if constexpr (requires {Component::to_string();})
-		{
-			return Component::to_string();
-		}
-		else
-		{
-			auto name = util::type_name<Component>();
-			if (auto pos = name.find_last_of(':'); pos != std::string::npos)
-				name = name.substr(pos + 1);
-			return name;
-		}
-	}
-
-	template <typename Component>
-	std::string describe(Component const & component)
-	{
-		if constexpr (requires {component.to_string();})
-		{
-			return component.to_string();
-		}
-		else
-		{
-			return describe<Component>();
-		}
-	}
-
-}

libs/ecs/include/psemek/ecs/detail/table.hpp

@@ -11,7 +11,6 @@
 #include <memory>
 #include <vector>
 #include <optional>
-#include <string>
 
 namespace psemek::ecs::detail
 {
@@ -81,8 +80,7 @@ namespace psemek::ecs::detail
 
 		std::size_t memory_usage() const;
 
-		std::string describe() const;
+		std::string describe_short() const;
-		std::string describe(std::uint32_t row) const;
 
 	protected:
 		std::uint64_t hash_;

libs/ecs/include/psemek/ecs/detail/to_string.hpp

@@ -0,0 +1,43 @@
+#pragma once
+
+#include <psemek/util/type_name.hpp>
+
+#include <string>
+
+namespace psemek::ecs::detail
+{
+
+	template <typename Component>
+	std::string component_name()
+	{
+		if constexpr (requires {Component::name();})
+		{
+			return Component::name();
+		}
+		else
+		{
+			static std::string const result = []{
+				std::string name = util::type_name<Component>();
+				if (auto pos = name.find_last_of(':'); pos != std::string::npos)
+					name = name.substr(pos + 1);
+				return name;
+			}();
+
+			return result;
+		}
+	}
+
+	template <typename Component>
+	std::string component_to_string(Component const & component)
+	{
+		if constexpr (requires {component.to_string();})
+		{
+			return component.to_string();
+		}
+		else
+		{
+			return "";
+		}
+	}
+
+}

libs/ecs/include/psemek/ecs/inspect.hpp

@@ -0,0 +1,19 @@
+#pragma once
+
+#include <psemek/ecs/detail/component_registry.hpp>
+
+namespace psemek::ecs
+{
+
+	struct entity_inspection_info
+	{
+		struct component_inspection_info
+		{
+			util::uuid uuid;
+			detail::component_registry::component_info const * info;
+		};
+
+		std::vector<component_inspection_info> components;
+	};
+
+}

libs/ecs/source/container.cpp

@@ -1,5 +1,6 @@
 #include <psemek/ecs/container.hpp>
 #include <psemek/util/assert.hpp>
+#include <psemek/util/string.hpp>
 
 #include <algorithm>
 
@@ -52,11 +53,47 @@ namespace psemek::ecs
 		return {data.table, data.row};
 	}
 
-	std::string container::describe(handle entity) const
+	entity_inspection_info container::inspect(handle entity) const
 	{
-		assert(alive(entity));
+		entity_inspection_info result;
 		auto const data = entity_list_.get_entities()[entity.id];
-		return data.table->describe(data.row);
+		for (auto const & column : data.table->columns())
+		{
+			auto const uuid = column->uuid();
+			result.components.push_back({uuid, component_registry_.get_info(uuid)});
+		}
+		return result;
+	}
+
+	std::string container::describe_short(handle entity) const
+	{
+		return entity_list_.get_entities()[entity.id].table->describe_short();
+	}
+
+	std::string container::describe_detailed(handle entity) const
+	{
+		static std::string const indent = "  ";
+
+		std::string result;
+
+		auto const data = entity_list_.get_entities()[entity.id];
+		for (auto const & column : data.table->columns())
+		{
+			auto const info = component_registry_.get_info(column->uuid());
+			result += info->name;
+			result += "\n";
+
+			auto const ptr = column->data() + column->stride() * data.row;
+			auto value = info->to_string(ptr);
+			if (!value.empty())
+			{
+				result += indent;
+				result += util::replace_all(util::trim(std::move(value)), "\n", "\n" + indent);
+				result += "\n";
+			}
+		}
+
+		return util::trim(result);
 	}
 
 	bool container::can_clone(handle entity) const
@@ -190,7 +227,7 @@ namespace psemek::ecs
 
 		table_container_.apply([&](detail::table & table)
 		{
-			result.tables.push_back({table.describe(), table.row_count()});
+			result.tables.push_back({table.describe_short(), table.row_count()});
 		}, {}, {});
 
 		return result;

libs/ecs/source/detail/table.cpp

@@ -1,5 +1,6 @@
 #include <psemek/ecs/detail/table.hpp>
 #include <psemek/ecs/detail/unordered_component_hash.hpp>
+#include <psemek/ecs/detail/to_string.hpp>
 
 #include <algorithm>
 
@@ -190,26 +191,14 @@ namespace psemek::ecs::detail
 		return result;
 	}
 
-	std::string table::describe() const
+	std::string table::describe_short() const
 	{
 		std::string result;
-		for (std::size_t i = 0; i < columns_.size(); ++i)
+		for (auto const & column : columns_)
 		{
-			if (i > 0)
+			if (!result.empty())
 				result += ";";
-			result += columns_[i]->describe();
+			result += column->name();
-		}
-		return result;
-	}
-
-	std::string table::describe(std::uint32_t row) const
-	{
-		std::string result;
-		for (std::size_t i = 0; i < columns_.size(); ++i)
-		{
-			if (i > 0)
-				result += ";";
-			result += columns_[i]->describe(row);
 		}
 		return result;
 	}